As electronic devices and the integrated circuits evolve and become more complex, the manufacturing processes which produce these semiconductor devices must also evolve. Numerous chemical components are utilized in the production of a single integrated circuit, all of which need to be provided and distributed within the semiconductor manufacturing facility. Liquid distribution systems take the required liquid chemicals from their storage point, and provide them to the end point of use, which is often the semiconductor processing tool.
One factor to successful semiconductor manufacture is the maintenance of the liquids being distributed. The concentration of the liquids distributed is often a critical aspect of the processes utilized for semiconductor manufacture. Accordingly, it is essential that the concentration of the liquids utilized in the distribution system be correct. One method for checking the accuracy of the concentration utilized is through concentration sensors which allow for the monitoring if the concentrations of the liquids that pass therethrough. As is the case with most sensors, these concentration sensors must be periodically checked and calibrated to ensure that they function properly.
Consequently, there exists a need for one or more methods to determine if there is a need to calibrate the concentration sensors in both closed systems and open systems.